It was a nightmare before church for two young Bronx sisters, who had to fend off a man who allegedly exposed himself as they walked to their house of worship, police said.

The girls, ages 12 and 7, were walking on East Tremont Avenue near Barkley Avenue in Throggs Neck Wednesday afternoon to a church function when the man — wearing a “The Nightmare Before Christmas” T-shirt — hopped out of his car, police said.

The perv allegedly exposed himself, asked the kids for directions to McDonald, and then got back in the light colored Subaru and took off.

The suspect is between 30 and 40 years old, around 5-foot-10, and was last seen wearing a black T-shirt with a logo of Jack Skellington, the main character from “The Nightmare Before Christmas.” He also wore khaki shorts and carried a jacket, cops said.